7 Key Shark Habitats That Need Conservation Now
Photo: USFWS Pacific/Creative Commons
Life isn't a walk in the park -- or a swim in the surf -- for sharks: They're threatened not only by fisheries, the shark finning industry, and pollution, but they're also saddled with a terrible reputation.
In reality, these apex predators are key to the health of the entire ocean, because as their numbers change, so do the behaviors, feeding habits, and populations of every creature underneath them in the food chain, from seals to sea grass.
And if we're going to be serious about shark conservation efforts, it doesn't just mean banning shark finning -- although that would be a good start. We have to also look at the other places key to sharks' survival: the mangroves that offer a place for baby sharks to thrive, the sea mounts that are home to plenty of food, the seal rookeries that offer a reliable source of nutrition, and more.
1. Coral Reefs
Coral reefs provide countless benefits to humans, from protecting shores from heavy waves to helping scientists make medical advances, and they're also intricately tied to sharks: A monitoring program in Belize has shown that the population of sharks on a reef is one easy way to measure the reef's health.
As top predators, the sharks also help keep the reef ecosystems in balance, maintaining diversity and preventing smaller fish from damaging the reefs with their expanding populations. Of course, the sharks benefit from healthy reefs, too: They're home to plenty of food.
2. Sea MountsPhoto: tanjila/Creative Commons
You may not have heard of sea mounts before, but the name is pretty self-explanatory: They are undersea mountains that aren't tall enough to be seen from the top of the water.
Sea mounts are also one of the main gathering spots for scalloped hammerhead sharks, which congregate by the hundreds in the sea mounts in Sea of Cortez and the Gulf of California.
According to ReefQuest, the hammerheads in these areas are developing their social skills while also using the lava signature from the sea mount as "magnetic highways" to move from spot to spot. (The feeder fish that thrive by sea mounts also help keep the sharks clean.)
3. MangrovesPhoto: Wikimedia Commons
The mangrove swamp in Bimini, Bahamas, has become one of the most important shark study spots in the world, since hundreds of baby lemon sharks gather there every summer to use it as a nursery.
Lemon sharks -- a larger member of the species that swims in the Western Atlantic -- thrive in the mangrove lagoon because it's safe and full of food. Sharks are on their own almost immediately after their born -- parents don't stick around to raise them -- so the protected areas offer a good chance of survival into adulthood.
4. Isla HolboxPhoto: Marcel_Ekkel/Creative Commons
Whale sharks love the waters off Isla Holbox, a tiny island near Mexico, because its tropical waters provide the perfect environment for feeding and mating.
Unfortunately for the sharks, their presence in the area has drawn thousands of tourists to an island that is home to just 1,600 year-round residents, causing serious problems for the health of the region and the well-being of the sharks that the tourists come to swim with.
5. Marine ReservesPhoto: puuikibeach/Creative Commons
You wouldn't think that an area already designated as a marine reserve would require extra attention to keep sharks safe, but some illegal fishermen see these protected areas as a profit-filled area to haul in a giant catch.
In July 2011, authorities from Ecuador caught a fishing boat leaving the Galapagos Islands national park with 357 dead sharks on board -- a number that one biologist from the Galapagos Science Center says makes it "the largest shark seizure in its history."
Marine reserves are often home to many different kinds of sharks -- in this case, the dead species included blue sharks, Galapagos sharks, hammerhead sharks, and tiger sharks, among others -- so enforcing anti-fishing and finning laws is even more critical to the area's biodiversity.
6. Guadalupe IslandPhoto: Wikimedia Commons
Areas where seal pups congregate are key to shark survival because they offer a critical -- and plentiful -- source of food. One example: Guadalupe Island, off the coast of Baja California, where dozens of Great White sharks return each summer when the seal pups are born.
The sharks leave the island in December and spend a little more than six months trolling the open waters, before returning in July. Researchers from the Marine Conservation Science Institute have tagged, photographed, and studied the behavior of the sharks near Guadalupe Island since 1999, identifying more than 116 individual sharks and keeping track of their migration patterns.
7. Shark Finning AreasPhoto: Christian Haugen/Creative Commons
It's nearly impossible to pinpoint one area that offers the greatest threat to sharks from finning -- the process where fisherman catch the shark, cut off their fins for soup, and throw them back to die -- because it happens all over the world.
But the government of Taiwan is taking a first step toward stopping the process: They've announced that fishermen will no longer be allowed to bring in dismembered sharks, hoping that the fishermen will stop finning (or at least have room on the boats for fewer sharks). But as Michael points out, the success of this ban will depend entirely on how well it is enforced.